The United States and Japan will step up their defence cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

More frozen berries recalled over hep A

More frozen berry products have been recalled due to possible hepatitis A contamination, with at least five people contracting the infection in the food scare.

Victorian company Patties Foods announced on Sunday it was expanding its recall to include all 300g and 500g packs of Creative Gourmet Mixed Berries.

On Saturday, all 1kg packs of Nanna's Frozen Mixed Berries were recalled when the Victorian Health Department warned of a potential Hepatitis A contamination.

Patties Foods CEO Steven Chaur said the wider recall was a precautionary measure.

"We have decided that all our frozen Mixed Berries should be recalled until such time as we receive the results of further laboratory tests," Mr Chaur said.

"The recall is an important step to ensure public safety and confidence."

The suspect berries were packed in China before distribution in Australia.

At least three people in Victoria, and two in NSW, who have eaten the frozen berries have since been diagnosed with hepatitis A.

Symptoms include abdominal pain, nausea and fever as well as yellow skin and eyes, and anyone experiencing these symptoms are urged to see a doctor.

"An investigation by all health agencies is underway but at this early stage we are not sure how many people may be affected," said Dr Vicky Shepherd, director of NSW Health's Communicable Diseases Branch.

"There is the potential that others may be sick with hepatitis A now, or develop the disease over the coming weeks."

Supermarkets have been told to pull all of the recalled berry products from sale.

Households who have the recalled products in their freezer are advised to bin them, or return them to the place of purchase for a cash refund.

Hepatitis A is spread when traces of faecal matter containing the virus come in contact with hands, water or food and then enter a person's mouth.

* Concerned consumers can call Patties Foods on 1800 650 069.

RECALLED:

* Nanna's Mixed Berries 1kg, up to and including Best Before Date 22/11/16

* Creative Gourmet Mixed Berries 300g, up to and including Best Before Date 10/12/17

* Creative Gourmet Mixed Berries 500g, up to and including Best Before Date 06/10/17.